Stroke indicating mechanism for riveting machines



Sept. 27, 1955 H. R. FISCHER ET AL 2,718,868

STROKE INDICATING MECHANISM FOR RIVETING MACHINES Original Filed Deo. l5, 1943 2 Sheets-Sheet l AT TOR IVE-Y Sept. 27, 1955 H. R. FISCHER ET AL 2,718,868

STROKE INDICATING MECHANISM FOR RIVETING MACHINES Original Filed Dec. 13, 1943 2 Sheets-Sheet 2 United States Patent Oce STROKE INDICATING MECHANISM FOR RIVETING MACHINES Howard R. Fischer and James A. Roberts, Utica, N. Y., assignors to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application Iuly 8, 1950, SerialNo. 172,668, which is a division of application Serial No. 514,068, December 13, 1943. Divided and this application December 29, 1951, Serial No. 264,219

1 Claim. (ci. 11s- 124) 514,068, filed December 13, 1943 relating to compressor riveters and now abandoned, and the application of Howard R. Fischer and James A. Roberts, Serial No. 172,668, tiled July 8, 1950, and relating to a stroke adjuster for riveting machines.

It is an object of the invention to provide a stroke indicating mechanism for a riveting machine whereby the length of the power stroke of the uid actuated piston can be visualized when setting up the test runs of the machine.

It is another object of the invention to provide an indicating mechanism for measuring the length of stroke of a fluid actuated device of a riveting machine which can be conveniently located within the machine frame with its handle projecting from beneath the machine frame and readily accessible for adjustment to its set position and wherein'indicating marks or indicia can be easily read.

Other objects of the invention are to provide an indicating mechanism for determining the length of stroke of a power actuated riveting tool for riveting machines, which is of simple construction, inexpensive to manufacture, has a minimum number of parts, compact, convenient to use and eicient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawing, in which:

Fig. 1 is an enlarged side elevational view of the top part of a riveting machine employing the indicating mechanism of the present invention, portions of the same being broken away to show the interior construction thereof;

Fig. 2 is a vertical sectional view taken on line 2-2 of Fig. 1 and looking in the direction of the arrows thereof;

Fig. 3 is an enlarged top plan view of the indicating mechanism removed from the machine;

Fig. 4 is an end elevational view of the indicating mechanism;

Fig. 5 is a side elevational view of the indicating mechanism with one side of the channel portion broken away;

Fig. 6 is a fragmentary side elevational View of the riveting machine showing the arrangement of the jaws, the

riveting tools therein and the top fluid actuating mechaj nism therefor.

Referring now to the iigures, a riveting machine generally indicated at 30, Fig. 6, consists mainly of a yoke 31 having upper and lower opposed jaws 32 and 33 and supported rigidly upon a column 34 that extends from a base, not shown` The jaws have considerable length and the yoke is made of material having great strength, toughness and elasticity, such as boiler plate steel, in o rder` to permit the development of a riveting pressure of many tons, `with a consequent spreading apart of the jaws 32 limit or developing fatigue in the metal' thereof.

In the lower jaw 33, Fig. 6, there is mounted a stationary rivet supporting tool, dolly or anvil 36 which is normally xed to the yoke, but which may be adjusted vertically relative thereo.

The upper jaw 32 has a complementary movable riveting tool or set 37 carried by plunger 38 and capable of being brought down during the riveting `operation toward the stationary rivet supporting tool or anvil 36. The plunger 38 is slidably mounted for vertical movement in vertically spaced bushings within the jaw 32, only the upper bushing being shown at 39, Fig. 1, and the lower one being in the lower end of the jaw and not shown. These bushings are xed in a bore 42 and the plunger 38, as shown in Fig. 6 will be projected downwardly through the bottom of the upper jaw. The plunger 38 carries the movable riveting tool 37 on its lower end which is vertically aligned with the stationary tool or anvil 36. A tool anchoring rod 44 runs through the plunger 38 and holds the rivet set 37 on the plunger.

The anchoring rod 44 has a shoulder 44', which engages Y a corresponding seat 38 in the plunger 38 to hold the rod against downward displacement through the plunger 38 and the movable riveting tool 37 on the end of the plunger. The upper end of the rod 44 is hollow and has a slot 45 in which a key 46 is tted, one end of the key 46 slides in a keyway 47 of upper bushing 39. The upper end of the rod 44 is hollow and has slots 48. The key 46 extends through the slots 48 in the upper end of rod 44 and slots 45 of the bushing by its engagement with the keyway 47 holds the entire assembly against rotation in the jaw 32 and particularly prevents the rotation of the rod 44 relative to the plunger 38. A spring pressed detent element 49 is slidable in the upper hollowed end of the rod 44 and presses against the key 46 to urge the rod 44 downwardly through the plunger 38 and the shoulder 44 of the rod against the shoulder 38 of the plunger 38.

At its front end, the yoke jaw 32 extends rearwardly and has transverse bolts S3 to connect upper U-shaped frame S4 with the jaw. The front end of the frame 54 is closed bya plate 55. A uid actuating cylinder 56 is bolted to the rear end of the frame. This cylinder has a fluid chamber 57. A control valve housing 58 is, in turn, connected'to the rear end of the iluid actuating cylinder. Within the U-shaped frame 54 is an operating cam lever 59 pivotally connected to the frame 54 by pivot pin means 61. The cam lever 59 has a nose 62 that engages the upper end of the tool plunger 38 and during the operation of the machine serves to depress the plunger 38 to set the rivet.

The cylinder chamber 57 contains a reciprocal pistonl of cam lever S9 while the upper roller 69 rolls along a` top rail 71 secured to the top of the frame 54 by screw bolts 71' and 71". As shown in Figs. l and 2, the rollers 69 and 69 roll over each other thereby relieving the roller block 68 of a large part of the reaction which is transmitted from the cam lever 59 and upwardly through the rollers to the top rail 71 and yoke frame 54.

An inner piston rod 72 is screwed at its forward end into the shank portion 67 of the forked roller block 68 and passes through hollow piston 64. On the rear end of the rod 72 is an increased diameter portion 72' which Patented Sept. 27, 1955l carries sleeve 73. Thevslreeve 73wis held against axial displacement by screw bolt 74. The sleeve 73 engages a washer 74 abutting the rear face of the piston 63.

If the piston- 63 is'retracted, lower roller 69 eng-agesa depression 753 in the upper edge of Athe cam lever 59 and. rear pivot pin means 61 thereof, the; plunger 38 will be elevated under the action offits spring, not shown,- and the cam-lever 59 will thereby be raised upwardly.

When the roller block 68 is forced forwardly by the piston 63,Y whichV is driven by fluid under pressure, entering. chamber 57 from valve housing 58, the upper roller 69 engagingt-he rail 71v and the lower roller 69 engagingthe cam.. lever 59,- the cam. lever 59 will. be progressively swung down with` force andthe tool plunger 38 with the set A37 is caused to descend toward the riveting tool or dolly 36 in the lower jaw 33 ofthe yoke 31. A-valve 131 can be adjusted to regulate the piston velocity on the power stroke in a manner describedv in. the prior patent application, Serial` No.. 172,668. A magnetic coil device 134 operates the control valve 58l to which iluid under pressure is supplied by means o fv a hose 87 connected to aiitting 87 in the valve housing 58.

In order to enable the operator to determine the amount of stroke of the piston in the forward direction, there is provided according to the present invention a visual indicating` device indicated generally at l150.- This indicating device 150` comprises a tubular guide 151 arranged in the lower portion of frame 54 and extending parallel to the direction of travel of they piston 63. A bent indicatingy rod 153 has a horizontal portion 152 which is slidably guided by the tubular guide 151. The rear end of the indicating rod 153 has a laterally extending handle portion 154 with a knob 154 thereon accessible beneath the cylinder 56 in order to manually withdraw the indicator rod' and to return it to its rearward or set position. The indicator rod 153 has a vertical portion 155 which is pushed forward by the roller block 6'8 until the piston 63 has come to the end ofV its working stroke, so that the indicator rod 153 comes to rest in the attained extreme forward position and will remain in that position until again set.

The vertical portion 155 of the rod 153 is held in its vertical position by engagement with sides of the U-shaped channel portion 156 of tubular guide 151 which lies intermediate cylindrical portionsl 157 and 158, Fig. 5. Thus, the vertical portion 155 of the rod 153 may be carried through the length of channel portion 156. Suitable indicia or graduations may be provided on the horizo'ntal portion 152 of the indicating rod 153 andl near the handle end thereof to indicate the distance that the hori-l zontal portion 152 projects rearwardly of the forward en'd of the cylinder portion 158 of the guide member 151. A bracket '9 supports the tubular guide 151 on the inner'wall of the frame 54. It has' a vertical ange p rovided with a hole 162 to' receive a cap screw 160, Fig. 2,. that xes the bracket to the inner wall ofthe U-shaped frame 54. The vertical portion 155 has an indenture 1515"` to accommodate an internal reinforcing ribv 54 on theinner wall of the U-sha`ped frame 54.

f a long rivet and heavy work pieces should be worked by' the machine,- the handle or knob 154 will obviously not be brought as far forward asv when smaller rivets and lighter work pieces' are worked. The forward limit positieni may be noted by the operator with a test rivet. The testing proceeds until the test settingl of' the test rivet is virtually perfect. The machine will then have been adjusted and fixed to operate to exactly the same extent and manner thereafter. Y

The upper edge 59' of the cam lever 59 has a position ot limited length and is so shaped that as the rollerv 69' passes thereover, there is a uniform mechanical advantage of speed ratio between piston 64 and thek plunger 38. Uniformi-ty of pressure for the rivetI isl obtained by terminatin'g each power stroke within the limits of uni formpressure range. It' the stroke indicator shows thatv 4 the power stroke is too short or too long for this purpose, the operator may adjust the forwardl stroke by lowering or raising the dolly or anvil 36 on the lower jaw 33 of the yoke 31, Fig. 6.

A micrometer gauge arrangement is provided for the adjustment of dolly 36 which includes a screw 163 and a knurled adjusting knob 168'. A loc'lr-ingknoby ll77if1xes the screw 163 in' place after the adjustment thereof has been eiected.

This machine' h'asa return stroke adjuster comprising a hook extensionv 181 near they fulcrum end of thel lever 59 which is engaged by a cam 182. The cam has a collar portion 18'2' that is fixed' to the horizontal shaft 15S-3' which is' supported for longitudinal and rotative movement in and between the spacedy walls of U-shaped frame 54. One end of the shaft has a forked extension 184 that carries a transverse pin 185 which serves as a pivotal support for the upper end of a stroke adjusting lever 186. This lever 186- has adepending and outwardly bent; handle portion 186. versal movement and is ad'apted to swing longitudinally withi respect tothe shaft 1-83 about the axis of. pin 185 and also is adapted to swing', in unison with the4 shaft 183 about its axis. The range of movement of the lever 186- is limited by a ratchet toothed segment 187 and a guide segment 188, ixed to the side of the frame 54 by screws 189, Fig. 2. The space between the segments 187 and 188 is suicient to allow lever 1S6'to travel forward: and rearwardY without engaging the ratchet toothed segmenti` 187 when av light pressuref is exerted on thev lever 186 against the guide segment 188 upon movement of' the lever to a new position of adjustment.

This outward pull or longitudinal adjustment of the lever 186 is resisted by a spring 191 which will return the lever to the ratchet toothed segment upon release of the lever. A spring. 194 surrounds sha-ft 183 and tends to holdl the shaft inthe position. shown in Fig. 2, but will be compressed as the shaft 183` is moved to the right to free the cam so that it releases the cam lever 59 and the plunger 38 for upward movement in response to the plunger spring.

A stop lever 195 is pivoted at 195 upon the end plate 55 and is engaged by the roller block 68. As it pivots, a control switch 196 is operated to interrupt the work stroke of the piston 63 and permit its return. The piston movement. is automatically reversed thereby.

It. should now be apparent that there has been provided a`n indicating mechanism for determining the length of stroke of the riveting tool for riveting machines that can be set for` operation by a simple adjustment' of a rod to a set position for engagement by the moving part ofthe fluid actuating device. The extent of movement of the riveting tool can be determined by noting the position. of the handle of the mechanism after the iilrst stroke or'. from indicating marks disposed on the rod that is' s'lidable in the sleeve of: the mechanism. The iindicating' mechanism lies on the inner side of the U-shaped frame of the machine and is accessible from the open underside thereof.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the appended claim.

What is claimed is:

An indicator mechanism for registering the maximum stroke of a variable stroke movable machine element comprising a guide means adaptable for xed positioning relative the movable element and having a hollow' cylindrical portion and an open U-shaped channel portion, a' free moving indicating rod slidably supported in the guide means' and having at one end a rst portion proje'ctingv through the open channel to be engaged by the movable element whereby the rod is' urged to a position of repose indicative of the maximum stroke of the movable element and e second portion at the end oppositethe first portion, said second' portion sfidably tting within The lever 186' is thus supported for inni ...rf s

References Cited in the ile of this patent UNITED STATES PATENTS Thompson et al Jan. 6, 1891 Souther May 30, 1922 Havens Nov. 18, 1930 Wilson Apr. 17, 1945 

